https://www.christies.com/lot/lot-lee-bontecou-third-stone-and-untitled-etchi-3973983/?from=salesummery&intobjectid=3973983
Third Stone; and Untitled Etching, from The National Collection of Fine Arts, Washington D.C. Portfolio (Universal Limited Art Editions 3; and 10)
lee bontecouthirdstoneuntitledetching